Ambulance dispatch versus general practitioner home visit for highly urgent out-of-hours primary care

Background Patients with life-threatening conditions who contact out-of-hours primary care either receive a home visit from a GP of a GP cooperative (GPC) or are handed over to the ambulance service. Objective The objective of this study was to determine whether highly urgent visits, after a call to the GPC, are delivered by the most appropriate healthcare provider: GPC or ambulance service. Methods We performed a cross-sectional study using patient record data from a GPC and ambulance service in an urban district in The Netherlands. During a 21-month period, all calls triaged as life-threatening (U1) to the GPCs were included. The decision to send an ambulance or not was made by the triage nurse following a protocolized triage process. Retrospectively, the most appropriate care was judged by the patient's own GP, using a questionnaire. Results Patient and care characteristics from 1081 patients were gathered: 401 GPC visits, 570 ambulance responses and 110 with both ambulance and GPC deployment. In 598 of 1081 (55.3%) cases, questionnaires were returned by the patients' own GP. About 40% of all visits could have been carried out with a lower urgency in retrospect, and almost half of all visits should have received a different type of care or different provider. In case of ambulance response, 60.7% concerned chest pain. Conclusion Research should be done on the process of triage and allocation of care to optimize labelling complaints with the appropriate urgency and to deploy the appropriate healthcare provider, especially for patients with chest pain

Matrix metalloproteinase-12 is expressed in phagocytotic macrophages in active multiple sclerosis lesions

Matrix metalloproteinases (MMPs) are proteases involved in extracellular matrix (ECM) remodeling, leukocyte infiltration into lesions and myelin degradation in the central nervous system (CNS) disease multiple sclerosis (MS). We have investigated whether MMP-12 (macrophage metalloelastase) is expressed in MS lesions at various stages. In control patient tissue and (p)reactive MS lesions, only occasional microglial and astrocyte staining was detected. In contrast, in active demyelinating lesions, phagocytic macrophages were MMP-12 positive. A lower proportion of phagocytes was positive for MMP-12 in chronic active demyelinating lesions and inactive lesions. This suggests a role for MMP-12 during demyelination in MS

The expression profile of matrix metalloproteinases (MMPs) and their inhibitors (TIMPs) in lesions and normal appearing white matter of multiple sclerosis

In multiple sclerosis, matrix metalloproteinases (MMPs) are effectors of crucial pathogenetic steps, such as blood-brain barrier breakdown, invasion of brain parenchyma by immune cells and demyelination. However, only limited data are available on the types of MMPs induced in the course of multiple sclerosis, and on the role of their endogenous antagonists, the tissue inhibitors of metalloproteinases (TIMPs). We quantified the transcriptional expression of six MMPs and the four TIMPs in lesions and in normal appearing white matter (NAWM) from post-mortem multiple sclerosis brain tissue by real-time polymerase chain reaction, and compared levels with those in brain tissue from six control patients without neurological disease. The mRNA expression of MMP-7 and -9, but not of other metalloproteinases [MMP-2 and -3, and tumour necrosis factor (TNF)-α-converting-enzyme] was equally upregulated throughout all stages of lesion formation with active inflammation, and in most of matched NAWM tissue. The transcription of cytokines TNF-α/β and IL (interleukin)-2, known modulators of MMPs, was upregulated only in distinct stages of lesion formation, while their receptors were not induced at all, which suggests that additional signalling molecules participate in the sustained upregulation of MMP-7 and -9 in multiple sclerosis. None of the TIMPs showed a significant induction over baseline expression of controls. We hypothesize that an imbalance between MMP and TIMP expression may cause a persistent proteolytic overactivity in multiple sclerosis, that may be a factor for continuous tissue destruction, and hence for secondary disease progressio

Remyelinated lesions in multiple sclerosis: Magnetic resonance image appearance

Background: Various types of pathologic mechanisms in multiple sclerosis (MS) can alter magnetic resonance imaging (MRI) signals, and the appearance of remyelinated lesions on MRI is largely unknown. Objective: To describe the MRI appearance of remyelinated lesions in MS. Design: Comparison of postmortem MRI findings with histopathologic findings. Setting: Brain donations from a general community. Patients: Magnetic resonance images from 36 rapid autopsies yielded 161 areas that could be matched with histologic characteristics, including 149 focal T2-weighted abnormalities, with a range of signal intensities on T1-weighted images. In a subset of 49 lesions, magnetization transfer ratio could be determined. Main Outcome Measures: An observer blinded to the MRI findings assessed the presence of remyelination using light microscopic criteria; in 25 areas, in situ hybridization was used to assess the presence of oligodendrocytes expressing proteolipid protein messenger RNA. Results: Remyelinated areas were found in 67 lesions (42%): partial remyelination was present in 30 lesions (19%), whereas 37 lesions (23%) were fully remyelinated. Remyelinated lesions contained enhanced numbers of oligodendrocytes containing proteolipid protein messenger RNA. All areas with remyelination shown histopathologically were hyperintense on T2-weighted images. Strong hypointensity on T1-weighted images was significantly associated (X2 = 29.8, P<.001) with demyelinated and partially remyelinated lesions compared with fully remyelinated lesions. The magnetization transfer ratio of remyelinated lesions (mean [SD], 27.6% [41%]) differed (F = 46.3, P<.001) from both normal-appearing white matter (35.2% [32%]) and demyelinated lesions (22.3% [48%]). Conclusions: Remyelinated lesions return an abnormal signal on T2-weighted images. Both T1-weighted images and magnetization transfer ratio may have (limited) additional value in separating lesions with and without remyelination

Beneficial effect of modified peptide inhibitor of alpha4 integrins on experimental allergic encephalomyelitis in Lewis rats

An important event in the pathogenesis of the autoimmune disease multiple sclerosis (MS) is the recruitment of lymphocytes and inflammatory macrophages to the central nervous system (CNS). Recruitment requires adhesive interactions between the leukocytes and the microvascular endothelium, perivascular cells, and astrocytes in the CNS parenchyma. Previous studies using an animal model of MS, experimental allergic encephalomyelitis (EAE), have shown the involvement of the alpha4 integrin VLA-4 (beta4beta1). In the present study, the effect of a modified peptide inhibitor of alpha4 integrins on the clinical course and leukocyte infiltration during EAE is investigated. EAE was either induced actively, by immunizing Lewis rats with whole guinea pig MBP, or passively, by transfer of an MBP-specific T cell line. Treatment with the inhibitor (CS1 ligand mimic) completely prevented both clinical signs and cellular infiltration in passively induced EAE. Peptide treatment of actively induced EAE, which has a more severe disease course than the transfer model, significantly reduced clinical signs although the recruitment of inflammatory cells and induction of MHC class II expression was not prevented. The alpha4 inhibitor did inhibit the adhesion of lymphocytes to primary astrocytes in vitro suggesting a role for astrocyte-leukocyte interactions in the pathogenesis of induced EAE. Astrocytes were found to express an extracellular matrix protein distinct from fibronectin, which shows immune cross-reactivity with the CS1 domain of fibronectin. Our results show that small-molecule inhibitors of alpha4 integrins act therapeutically in EAE possibly by interfering with cell adhesion events involved in this autoimmune diseas